The invention relates to a coupling assembly connecting two tubular elements, in particular ends of two tubes of an air-conditioning system, having a bayonet lock in which the inter-engaged locking parts are rotated with respect to one another.
It is know, for example for the purpose of producing a coolant circuit, to connect individual tubes to one another at their ends. For this purpose, use is made of bayonet locks designed, for example, as quick-action couplings. The bayonet locks usually have two mutually associated, inter-engaging locking parts which, for the purpose of achieving a locked position, can be rotated with respect to one another and can be displaced with respect to one another in the axial direction.
The disadvantage with the known bayonet locks is that sealing is achieved exclusively via a radially shaped sealing element. In this case, said sealing elements are arranged, usually as sealing discs, between the two ends of the tubular elements. Such a quick-action coupling is unstable in relation to mechanical loading perpendicular to the axis of the two ends.
Furthermore, the sealing discs used each have two sealing surfaces, which butt against corresponding shaped sealing surfaces at the ends of the tubular elements. Said sealing surfaces are arranged in a manner radially offset with respect to the longitudinal center axis of the tubular elements, which is disadvantageous, in particular, if a pressurized medium is to be conveyed through the tubular elements. Furthermore, the size and the three-dimensional extent of the sealing surface is a measure of the pressure stability of such a seal; that is to say, the sealing surfaces are enlarged in the radial direction for the purpose of increasing this stability in the case of the known bayonet locks. The coupling is thus widened in the radial direction, and this results in a greater amount of space being required.
Also known are bayonet locks which, for the purpose of overcoming the above disadvantages of radial sealing elements, have axially shaped seals. For this purpose, usually one end of the tubular element is widened, in terms of its internal radius, to the external radius of the second tubular element. The two elements are then connected to one another axially. The two ends are thus designed as sealing elements, there inner or outer surface forming the sealing surface of the seal. This results, on the one hand, in an increase in stability of the bayonet lock in relation to transverse forces and, on the other hand, in an increase pressure stability as a result of the enlargement and the axial alignment of the sealing surface. The disadvantage is that, in the case of the known bayonet locks with an axial seal, specially formed tools are to be used, in part, for the purpose of releasing the connection.
It is also disadvantageous, in the case of the previously known bayonet locks, that, for fixing the coupling elements axially at the ends of the tubular elements, use is made of, in part, high-outlay arrangements, and that high outlay is involved for the purpose of fitting such a coupling element.
The object of the invention is to provide a coupling assembly of the generic type which is of straight forward design and in which it is possible to ensure good sealing action with low forces.
A coupling assembly having a bayonet-type locking feature is proposed in order to achieve this object. The coupling assembly has two locking parts each of which comprises two sub-elements. These sub-elements are fixed in the radial direction by two inter-engaging sleeves. It is possible to engage the lock at the ends of two tubular elements, and to remove the lock, without using an additional tool. Thus, it is possible to manually disassemble the coupling assembly. Since the locking parts each comprises a plurality of, preferably two sub-elements, the locking parts may also advantageously be subsequently fitted to, and removed from, a pipeline which has already been laid. In this case, the sub-elements of the locking parts are preferably configured such that they butt against one another in a planar manner and are fixed in position by the sleeves.
A development of the invention provides that the sleeves can be fixed in the axial direction by, in each case, one securing ring. A preferred embodiment provides that, when the locked position has been reached, this is indicated by a radial displacement of a moveable pin which is arranged in one of the inter-engaging sleeves.
A further preferred configuration of the invention provides that a first locking part comprises a sleeve into which a plug-in section of the second locking part can be latched. This achieves, in a straight forward manner, a positively and frictionally locking connection of the two locking parts to one another.
Furthermore, a preferred configuration of the invention provides that a sealing element is designed as an axial element which, when the components of the assembly are locked, is compressed in the axial direction. For this purpose, the sealing element preferably has shaped portions which can be displaced axially by the sealing surfaces without the latter being deflected radially in the process. The forces which are to be overcome by the axial compression of the shaped portions during transfer of the locking components into the locked position may be used simultaneously during unlocking of the bayonet lock, with the result that the forces which have to be applied from the outside for the purpose of releasing the assembly may be relatively low. As a result, it is also possible for the lock to be locked and unlocked without any additional tools.
Further advantageous configurations of the invention can be gathered from the rest of the features mentioned in the claims.